Now, lets look at the words planktonic and sessile. Planktonic means free-floating – think of plankton in the ocean, which are microscopic plants and animals floating and moving about in the ocean. This view is what many students have of bacteria when they leave biology class. While this is not incorrect it is also not a totally correct view of bacteria. Sessile means to be attached – think of a boy and girl dating. For the most part the boy and girl are “together forever” and will never separate. Bacteria actually congregate like this in natural (not laboratory) conditions and for the most part when they attach to a surface they are “together forever.” That statement, however, is not completely true. A disruption or agitation of the congregated bacteria can cause a break up of the community and the bacteria will float around and reattach in another community. This disruption can be equated to a more attractive classmate breaking up the “together forever” boy and girl.